Description of White Shark

﻿The white shark (Carcharodon carcharias), also known as the great white shark, white pointer, or white death, is one of the best-known sharks principally due to interest surrounding the occasionally fatal interactions between humans and this species. Nevertheless, surprisingly little is knownabout their biology. White sharks are large, active fish that are only infrequently encountered by humans and which have not survived long in the few attempts that have been made to keep them in captivity. Attempts to study the biology of white sharks are therefore limited to brief observations of their biology and what can be inferred from the anatomy of captured dead sharks.

White Shark Anatomy and Physiology

Like all sharks, the white shark possesses a skeleton composed of cartilage, a tough elastic connective tissue found in all vertebrates. The cartilage in the skeleton of white sharks is strengthened by deposits of calcium carbonate, but there is no true bone as in most other fishes. Like most sharks, the white shark has five pairs of gill slits located just in front of the broad pectoral fin and a heterocercal tail, in which the spinal column extends into the upper lobe. The tail, or caudal fin, of the white shark, as in all members of the family Lamnidae, is almost symmetrical and possesses a pronounced lateral keel at the point where the tail is attached to the body trunk. Such a lateral keel may improve the efficiency of the tail in swimming and turning and is a common element of many large, fastswimming fishes. The upper jaw of white sharks is suspended from the skull by ligaments rather than fused directly to the skull, as in most terrestrial vertebrates. This amphistylic suspension of the jaws allows them to be pushed forward and out, increasing the efficiency of the biting mechanism in a mouth that is located below and behind the broadly conical snout. White sharks, like all sharks, lack a gas-filled swim bladder to provide buoyancy in the water and rely on the lifting action of their fins and body shape to prevent them from sinking. The streamlined, spindle-shaped body, broad fins, and powerful, symmetrical tail of the white shark suit it well to a fast and powerful swimming style, and white sharks, like others in the family Lamnidae, are among the most active sharks. White sharks possess special modifications of the circulatory system in the body wall and central nervous system that are known as rete mirabile. These modifications permit the shark to return the heat generated by metabolism to the body core, rather than losing it to the surrounding water as in most fish. The rete mirabile allows white sharks to maintain a core body temperature that is higher than the surrounding water; this may provide an advantage to the shark by raising its metabolic rate and permitting greater activity in the cooler waters which they typically inhabit.